英语翻译To appreciate the significance of the proposed spatial C
英语翻译
To appreciate the significance of the proposed spatial CSbased
method in the array signal processing framework,it
can be compared to the conventional methods of the field
directionality estimation.According to the conventional methods,
the beamforming was typically utilized for the noise
filed directionality estimation,and 2-D azimuth sector was
scanned via generation of consecutive directional beams.As
a result,the azimuth resolution was a strong function of the
beamwidth and the array length.According to the proposed
CS-based method,outputs of each array element (rows in
the sensing matrix Φ) provide measurements for the spatially
compressive sensing reconstruction process.Therefore,the
number of available measurements is proportional to the array
length M.According to the compressive sensing theory,the
number of measurements that is required to reconstruct the
J-compressible signal is
M ≈ c2J/(logN)4 ,(15)
where N is the maximal number of distinguishable in the
bearing space signals.The expression in (15) means that for
the given array length M and the field directionality sparsity
J,the maximal number of the array responses to distinct
plane waves is N,which determines the angular resolution
of the estimated field directionality.The exponential relation
in (15) provided the potential for significant improvement in
the angular resolution.
V.SIMULATION RESULTS
The performance of the proposed spatial CS-based field
directionality estimation approach is evaluated in this section.
Consider a ULA with M = 30 elements,and inter-element
spacing d = λ/2.In the first considered scenario,five strong
far-field point sources received at the following bearing angles:
θ = [33o,60o,76o,90o,120o] with signal-to-noise ratios
(SNR):[20,10,15,20,15] dB,were simulated.In [12],the
WS was proposed and it was shown that this method outperforms
other field estimation methods.In this scenario,field
directionality estimation performance of the CS-based method
was compared to the WS.For the WS,a field directionality
was obtained from four array orientations 70o,80o,90o,100o.
Fig.1 shows an estimated field directionality for the CS and
the WS-based methods.This figure shows that the CS-based
estimator outperforms the WS estimator.